Bearing stress on concrete wall-slab junction
Bearing stress on concrete wall-slab junction
(OP)
Hi All,
Please see attached detail for Wall-Slab junction. The slab is supported on 40mm [~1.6"] bearing width which is equal to the thickness of the wall vertical reinforcement cover.
1. When calculating the bearing stress on on the support is it right to included the stress from the wall in addition to the stress from the slab reaction? see load-path on pic.
2. Considering the edge distances of the bearing area how do we evaluate the reduction of bearing capacity due to diagonal tensions as shown on the picture?
Thanks..
Please see attached detail for Wall-Slab junction. The slab is supported on 40mm [~1.6"] bearing width which is equal to the thickness of the wall vertical reinforcement cover.
1. When calculating the bearing stress on on the support is it right to included the stress from the wall in addition to the stress from the slab reaction? see load-path on pic.
2. Considering the edge distances of the bearing area how do we evaluate the reduction of bearing capacity due to diagonal tensions as shown on the picture?
Thanks..






RE: Bearing stress on concrete wall-slab junction
BA
RE: Bearing stress on concrete wall-slab junction
Yes, the slab is cast in place.
RE: Bearing stress on concrete wall-slab junction
2. If there is a reasonable amount of reinforcement running through the wall connecting the slabs, I would treat it the same as a monolithic pour. I would have been more concerned if the slabs had been precast with no ties across the wall.
BA
RE: Bearing stress on concrete wall-slab junction
- This detail is to be used on a multi-story building, do you think axial shorting of the shear wall will be able to close the shrinkage gap on the lower floor and engage the load path in question?
- Yes there will be enough top and bottom slab reinforcement running through sleeves on the wall to achieve flexural continuity, but the shear has to be transferred through the bearing width as there is no aggregate interlock and only uncertain dowel action.
Sorry for not providing the added information on my original post.
RE: Bearing stress on concrete wall-slab junction
BA
RE: Bearing stress on concrete wall-slab junction
RE: Bearing stress on concrete wall-slab junction
Hi Asixth, the sleeves crossing the wall are to be larger than the slab reo diameter and it will be hard to justify the dowel action of the slab reo crossing the wall.
The building is located in non-seismic area; the lateral diaphragm force that we dealing with is only wind and can be transferred by friction on the bearing area.
Its expensive for us to provide threaded inserts with threaded slab reo as you indicated on this this thread http://www.eng-tips.com/viewthread.cfm?qid=356331. Are there any other method that we can employ?
Thanks a million.
RE: Bearing stress on concrete wall-slab junction
1. Threaded inserts with rebate
2. Pullout bars with proprietary cast in rebate
Other than that it would conventionally forming and placing the walls followed by the slabs as you go up. As long as there is some anchored rebar across the interface it should work.
RE: Bearing stress on concrete wall-slab junction
BA
RE: Bearing stress on concrete wall-slab junction
RE: Bearing stress on concrete wall-slab junction
BA
RE: Bearing stress on concrete wall-slab junction
Beside further investigating the cost of threaded inserts as hokie noted above we are looking at using a cone shaped sleeves for each bar and pour the concrete on one side to minimize air-entrapment and add a small diameter [10mm] pull-out bars fully developed across the wall for easy of re-bending on-site.
If both options fail we will resort back to conventional method.
RE: Bearing stress on concrete wall-slab junction
RE: Bearing stress on concrete wall-slab junction
BA
RE: Bearing stress on concrete wall-slab junction
RE: Bearing stress on concrete wall-slab junction
Could you please post the name of the book that you referring from.